赤拟谷盗全基因组和EST中微卫星的丰度

微卫星是近年大力开发的一种分子标记,为了推进赤拟谷盗Tribolium castaneum(Herbst)遗传学相关研究,对赤拟谷盗全基因组和EST中由1~6个碱基重复单元组成的简单序列重复进行分析,进而对其微卫星的丰度和分布进行比较分析。微卫星在赤拟谷盗EST中的分布频率为1/0.87kb,其中单碱基重复序列占71.25%,是最丰富的重复单元,而六、三、四、二,五碱基重复单元序列分别占23.93%,2.94%,1.56%,0.17%,0.15%。全基因组中微卫星的分布频率为1/3.65kb,其中六碱基重复序列占61.96%,是最丰富的重复单元,而三,四,一,五,二碱基重复单元序列分别占14.35%,13.75%,4.68%,3.60%,1.69%。同时发现富含A和T碱基的微卫星占主导地位,富含G和C碱基的微卫星数量较少。进一步的分析显示,微卫星在每条染色体上的丰度存在很大的相似性。

Abundance of microsatellites in the entire genome and EST of Tribolium castaneum

Microsatellites are genetic markers that have made great advances in recent years. In order to improve the studies related to genetics of Tribolium castaneum(Herbst), simple sequence repeats of the entire genome and EST in T. castaneum with 1～6 bp nucleotide motifs were analyzed. Abundance of microsatellites across the genome of T. castaneum was analyzed and compared between all of the chromosomes. The results showed that the frequency of SSRs in the EST was 1/0.87 kb, among which mononucleotide repeat motifs appeared to be the most abundant type (71.25%), while the hexanucleotide, trinucleotide, tetranucleotide, dinucleotide and pentanucleotide repeats accounted for 23.93%, 2.94%, 1.56%, 0.17% and 0.15% of the total, respectively. The frequency of SSRs in the entire genome was 1/3.65 kb, of which hexanucleotide repeat motifs were the most abundant type (61.91%), while trinucleotide, tetranucleotide, mononucleotide, pentanucleotide and dinucleotide repeats were 14.35%, 13.75%, 4.68%, 3.6% and 1.69%, respectively. Meanwhile, the A-rich and T-rich repeats were predominant, whereas G-rich and C-rich repeats were rare. Further analysis demonstrated that the abundance of microsatellites in different chromosomes was to a great extent similar.